Case Studies: Current Projects
Robbins TBM to bore exploratory tunnel for Italian rail system
- Machine Type: Main Beam TBM
- Diameter: 6.3 m (20.7 ft)
- Tunnel Type: Exploratory
- Tunnel Length: 7 - 10 km (4.3 - 6.2 mi)
- Owner: Lyon Turin Ferroviaire
- Contractor: Venaus Societa Consortile (CMC di Ravenna, Strabag)
- Location: Venaus, Italy
Project Overview
The European Railway Network will be completed when the Lyon to Turin Base Tunnel links France and Italy through the East-West and North-South routes. Once complete, the tunnel will be one of the longest tunnels in the world at 53 km (33 mi).
Before boring the Lyon to Turin Base Tunnel the project owner, Lyon Turin Ferroviaire, elected to bore an exploratory tunnel. The initial tunnel will determine the ground conditions that exist, specifically where there is squeezing ground. This will allow the owner to select the correct type of machines with the right design to support the structural insitu stress of the tunnels.
Past attempts at excavating have revealed evidence of poor ground conditions in the areas to be bored. The information gathered from the exploratory tunnel will eventually be used on the Lyon to Turin Base tunnel, which will include twin train tunnels, 11 - 12 m (36 - 39 ft) in diameter.
The joint venture Venaus Societa Consortile (CMC di Ravenna and Strabag) chose a 6.3 m (20.7 ft) diameter Robbins Hard Rock Main Beam TBM for the exploratory tunnel. The TBM has several special features to effectively gather the information that is needed.
The machine is equipped with panel erectors for placing steel panels in the tunnel, allowing ground support directly behind the cutterhead. The machine can also keep the invert stationary and overbore by 200 mm (8 in), allowing it to continue boring in squeezing ground.
The probe drill on the machine is equipped with 360-degree capabilities to allow probing in any direction. Therefore, the owner can collect core samples from any location in the tunnel.
The machine features 17 inch (432 mm) cutters and can generate a cutterhead thrust of 12,144 kN (2,730,000 lb). The TBM also has a maximum cutterhead torque of 2,082,885 N-m (1,536,257 lb-ft).
Updates of this project will be posted as boring commences.
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For more information on this project, visit http://www.ltf-sas.com.